In U.S. Pat. Nos. 5,896,712 and RE36,496, both of which are owned by the same assignee as is the present invention and both of which are incorporated herein by reference, skylight covers are disclosed. These skylight covers can be used in conjunction with the tubular skylights disclosed in U.S. Pat. Nos. 5,896,713 and 6,035,593 also owned by the same assignee as is the present invention and also incorporated herein by reference. These inventions represent advances over the prior art and one or more of them has found commercial success.
Briefly, a tubular skylight such as those mentioned above includes a tube assembly mounted between the roof and ceiling of a building. The top end of the tube assembly is covered by a roof-mounted dome or cover, such as the one disclosed in the above-mentioned '712 patent, while the bottom end of the tube assembly is covered by a ceiling-mounted diffuser plate. With this combination, natural light external to the building is directed through the tube assembly into the interior of the building to illuminate the interior.
As understood herein, when sunlight impinges on the earth at steep angles, e.g., during sunrise and sunset, much of the light reaching the skylight cover does not enter the tube and as such, does not get reflected through the tube and into the building. Accordingly, the present invention recognizes a need for a skylight cover that promotes the reflection light entering the skylight cover into the tube.